A new conversion efficiency world record for concentrator photovoltaic modules (CPV), of 36.7%, was recently set thanks to a research collaboration between the Fraunhofer Institute for Solar Energy Systems ISE and the French CPV developer Soitec (along with the French research center CEA-Leti, and the Helmholtz Center in Berlin).
The researchers from Fraunhofer ISE — based in Freiburg, Germany — have spent the last few years working on the CPV module technology known as FLATCON, utilizing fresnel lenses to bundle and focus sunlight onto miniature, super efficient solar cells. The new record was achieved by combining this work with the adaption of a new wafer bonding solar cell structure developed together with Soitec.
By incorporating the said four-junction (GaInP, GaAs, GaInAs and InP) solar cell structure into the Fraunhofer ISE module concept, sunlight can be concentrated “by a factor of 230 suns onto fifty-two 7 mm2 miniature solar cells, with the help of fifty-two 16 cm2 Fresnel lenses.”
“Naturally we are incredibly excited about this high module efficiency,” stated Dr Andreas Bett, who leads the CPV research at Fraunhofer ISE.
The new work, according to Dr Bett, proves that the high efficiencies of Soitec’s novel four-junction solar cells can be carried over to the module level.
RenewEconomy provides a bit more information:
Concentrator photovoltaic systems (CPV) are installed in sun-rich regions, where such systems produce solar electricity for less than 8 eurocents per kilowatt-hour.
The key to the technology is the solar cell efficiency and the concentrating optic. In the record module, the newly developed four-junction solar cell was combined with Fresnel lenses, which were manufactured by the industry partner ORAFOL Fresnel Optics based on a new Fraunhofer design.
This new work is expected (by the researchers) to be incorporated into commercially manufactured modules within the next one to two years.